Missile Defense and the North Korean Nuclear Threat

Trilateral missile defense could be a turning point in dealing with the North Korean nuclear threat.

Pyongyang’s saber-rattling of late, coupled with multiple rocket engine tests and increased activity at the regime’s Pungyung-ri nuclear test site, have led many in Washington and Seoul to believe that the DPRK is planning to conduct its fourth nuclear test and/or another long-range missile test to enhance the credibility of its nuclear deterrent. But while public attention is once again on the idea of a North Korean nuclear-tipped ICBM that could threaten the continental United States, the strategic ground is shifting.

Over the last nine to eight months the military balance on the Peninsula has tripped dramatically in favor of the U.S.-ROK alliance in terms of projecting land, sea and air superiority. In October 2013 for instance, the alliance introduced the concept of tailored “tit-for-tat” deterrence, significantly enhancing Seoul’s active defense posture and according to South Korean Minister of Defense Kim Kwan-jin, increasing the level of inter-alliance operability to “detect, defend, deter, and destroy” any future North Korean threat.

Meanwhile, the unabated proliferation of U.S. missile defense systems across the Asia-Pacific has progressively degraded Pyongyang’s strategic ability to deter Washington with a limited nuclear-tipped ICBM program. On top of these developments, South Korea successfully tested its Hyunmoo-2 cruise missile in April this year, which under Seoul’s 2012 renegotiated missile guidelines is able to hit any target inside North Korea.

This renewed emphasis on conventional warfare within the alliance is a serious challenge for Pyongyang, with the asymmetric war stance it adopted two decades ago rapidly losing its ability to deter. As a result, in something of a replay of early 2013, between February and March this year North Korea test-fired its new 300-mm multiple rocket launcher (also known as the KN-09), which is able to shell areas well beyond the greater Seoul area, and re-tested its aging Scud missile arsenal. Contrary to last year, however, when the DPRK deployed but refrained from firing its intermediate Musudan missile, the echelons in Pyongyang decided to send a signal by launching two mid-range Nodong missiles, which have not seen action since July 2009.

The resurfacing of the road-mobile Nodong is upsetting the regional balance of power on various levels. First, the Nodong represents the DPRK’s most reliable ballistic missile asset to threaten Seoul, Tokyo, and U.S. forces stationed on Okinawa. Second, according to The Military Balance 2014, published by The International Institute for Strategic Studies, “some analysts, including in the US Defense Intelligence Agency, believe that, after working on weaponisation for more than 20 years, North Korea is likely to have the ability to miniaturize and mount a nuclear weapon on its mid-range Nodong missiles.” And third, given that the two missiles launched earlier this year traveled only an abbreviated distance of 400 miles, Pyongyang seems to be eager to showcase its ability to deliver a higher payload over a shorter distance and thereby compensating for the missile warhead’s uncertain re-entry capabilities.

Pyongyang’s strategic intentions with the reappearance of the Nodong are not entirely clear. Preliminary analysis however suggests that the emphasis on road-mobile systems combined with the DPRK’s low-yield nuclear tests in the past is indicative of a tactical nuclear program rather than a long-range strategic one.

With Congress hardly likely to warm to the idea of redeploying U.S. tactical nuclear weapons to South Korea as a mean to balance against the North, the Republican dominated House of Representatives instead passed the National Defense Authorization Act for the Fiscal Year 2015 (H.R. 4435) on May 22 which, if enacted, would require SecDef Hagel to “identify opportunities for increasing missile defense cooperation among the United States, Japan and the Republic of Korea.”

In late April, the same concept of trilateral cooperation surfaced during President Obama’s visit to Tokyo, when U.S. National Security Adviser Susan Rice discussed trilateral missile defense cooperation with Prime Minister Abe. While Japan certainly welcomed the U.S. initiative, given Abe’s vocal push towards collective self-defense, Washington’s renewed efforts to deepen cooperation among its East Asian allies is expected to meet some political resistance in South Korea. The experience of Seoul’s failure to sign the General Security of Military Information Agreement (GSOMIA) and the Acquisition and Cross-Servicing Agreement (ACSA) in 2012 combined with the lingering historic animosities between Japan and South Korea, has led many in the Obama administration to tread carefully. Hagel’s visit to Singapore last weekend, where he met with his South Korean and Japanese counterparts on the sidelines of the Shangri-La Dialogue, was thus an important step in creating a positive atmosphere for any future talks.

Indeed, trilateral missile defense cooperation is the long awaited 21st century solution to the persisting Cold War problems on the Korean Peninsula. It circumvents Washington’s extended deterrence credibility problem, by creating cross-alliance mechanisms that naturally enhance local defense postures. At the same time the focus on theater missile defense is lowering expectations on the use of the U.S. nuclear umbrella and avoids the necessity of answering the North Korean nuclear threat with a nuclear response.

For Washington the trilateral approach is the perfect solution to managing Pyongyang’s bellicose behavior in a regional security framework. Even for Tokyo, bilateral cooperation with Seoul is beneficial to the extent that South Korean forward-based radar stations will provide early tracking information on any inbound North Korean ballistic missiles. Seoul however, or so the argument goes, is in the peculiar position of buying into an agreement that offers very few political and military incentives other than being a responsible alliance partner.

On the one hand, critics have raised the issue that South Korea has to sway public opinion despite ongoing tensions with Japan. This is actually easier than most analysts outside the region tend to believe. According to a study by the Asan Institute for Policy Studies, public support for GSOMIA was at 60.4 percent in September 2013, and dropped only 10 percentage points even after Abe visited the Yasukuni shrine three months later. Indeed the same study goes on to explain that the public backlash that led Seoul to scrap GSOMIA in July 2012, was not due to anti-Japanese sentiment but rather President Lee Myung-bak’s attempt to “enact the agreement with virtually no public debate.” So while President Park Gyeun-hye’s low approval ratings after the Sewol ferry disaster may be of some concern in pushing through legislation on trilateral cooperation, there is no indication that the Park government will suffer the same public outrage as her predecessor.

On the other hand, policymakers in Seoul are divided on whether to join the U.S. missile shield or whether to develop its own system dubbed the Korean Air Missile Defense (KAMD). Essentially the question comes down to whether the Park administration is willing to buy into the narrative that missile defense is feasible and preferable to a mutual-assured destruction scenario on the Peninsula. Certainly, one of the major obstacles for selling the U.S. missile defense shield is the cost involved in continuously updating, upgrading, and modernizing the systems. Lockheed Martin’s Terminal High-Altitude Area Defense (THAAD) for instance costs around $800-950 million per battery, roughly the same amount Seoul would spend on building one of its KDX-III Sejong the Great-class Aegis destroyers, the largest surface warship currently commissioned in the South Korean Navy.

Nevertheless, THAAD and the emerging SM-3 Aegis Ashore system are currently the most promising candidates to defend South Korea from an incoming Nodong missile. Compared to Seoul’s current procurement plan, which is geared towards updating its existing systems to a Patriot Advanced Capability-3 (PAC-3), the differences in interception rate, range and altitude could not have any greater. PAC-3 boasts intercept altitude of 20-30 km, which, according to Choi Bong-wan, professor at the Graduate School of National Defense at Hanam University, translates into a reaction time of 1 second to incept an incoming Nodong missile. In contrast THAAD operates at altitudes of up to 150 km, resulting in a reaction time of 45 seconds, and the SM-3 Aegis Ashore system could push these boundaries even further to guarantee a successful intercept.

In fact, on May 27, the Pentagon proactively tackled Seoul’s problem head on by officially contemplating the deployment a THAAD system to Korea, according to a report in the Wall Street Journal. According to defense officials, “the U.S. could deploy its own THAAD system to South Korea temporarily, and then, in time, replace it with a system purchased by Seoul, […] or it could allow South Korea to purchase its own, and jump ahead in the queue for the system.”

While the details are still in limbo, the White House can counterintuitively rely on the broad support of Republicans who are willing to push missile defense in East Asia despite budget constraints at home. The Obama administration can also count on South Korean public support, which according to a poll conducted by the Asan Institute between March 16-18, has cited missile defense (18.7 percent) as the second most import issue for the U.S.-ROK alliance. The South Korean government’s initial response to the idea of joining a U.S. missile defense network has been cool, to say the least, but the U.S. looks perfectly willing to apply pressure.

For North Korea, trilateral missile defense cooperation would spell a devastating move. First, Pyongyang’s tactical nuclear deterrent would be dead on arrival with no bargaining position gained. Second, the U.S. nuclear umbrella would be supplemented by a multi-layered theater missile defense shield that would bring the most modern military systems to the Peninsula. And third, cross-alliance cooperation is naturally bound to spread from missile defense and information sharing to other issues involving joint military exercises and coordinated military responses. As a result, Washington’s strategic patience will prevail, Seoul’s and Tokyo’s defense posture will be enhanced, and Pyongyang’s attempt to deter the alliance will fail.

If there was ever any pressure on North Korea to denuclearize, trilateral missile defense would take the narrative to the next level. With successful deployment, Pyongyang would have to realize that however many nuclear tests it is willing to conduct, its nuclear adventure is coming to an end.

Stefan Soesanto is a non-resident James A. Kelly Fellow at Pacific Forum CSIS.